Method and apparatus for vaporizing liquefied petroleum gas



Jan. 25, 1949. A, Q TURNER 2,459,974

METHOD AND APPARATUS FOR VAPORIZING LIQUEFIED PETROLEUM GAS Filed July 16, 1941 2 Sheets-Sheet 1 Jan. 25, 1949. l A. c. TURNER 2,459,974

METHOD AND APPARATUS FOR VAPORIZING LIQUEFIED PETROLEUM GAS Filed July 16, 1941 2 Sheets-Sheet 2 Patented Jan. 25, 1949 METHOD AND APPARATUS FOR VAPORIZING LIQUEFIED PETROLEUM GAS Arthur C. Turner, Chilhowee, Mo.

Application July 16, 1941, Serial No. 402,637

13 Claims.

This invention relates to a method and apparatus for vaporizing liquefied petroleum gas such as butane and supplying the vapor for heating, lighting, cooking, and other purposes. Since liquefied petroleum gas pressures exist up to a degree commensurate with the temperature and since the vaporizing temperature of the liquid must be kept constantly uniform it has been the practice to store the liquefied gas in pressure containers that are buried in the ground for utilizing earth heat in maintaining the desired vaporizing temperature. However, such systems are diiiicult to service and it is necessary to transport Vthe liquefied gas and empty it into the VYunderground storage container which must be vented. Consequently much of the vapor in the storage tank is lost through the vent. Also when'the'heating appliances are supplied from the vapor accumulating in the storage tank, `large tanks are required to provide storage of sufcient capacity for supplying adequately the demand for gas, which resul-ts inr high apparatusrand installation cost. Another disadvantage is that vapor collected from the entire body of liquid varies widely in caloric value.

Another method of storing liquefied petroleum gas is to retain it in liquid form and deliver the liquid to a pressure regulator which reduces pressure of the gas to rthe vaporizing point. These systems fail to operate satisfactorily under all weather conditions for the reason that the expansion occurs so rapidly that the refrigeration effect results inY frosting over and freeze-up of the pressure regulator which interferes with the operation thereof, and in cold weather the rate of heat absorption necessary to effect vaporization of the liquid is not suflicient, with the result that liquid is delivered to the heating appliances producing fire and'eX- plosion hazards that make such systems impracticable.

Therefore, the purpose of the present invention is to provide 2 liquefied petroleum gas apparatus wherein the gas may be dispensed in liquid form through the use of high pressure containers or bottles which may be located above ground and readily connected to a Vaporizing apparatus located below ground, the liquid feed being maintained responsive to vapor pressure contained in the expansion space provided in such bottles and acting an the surface of the liquid thereby obtaining uniform calorific value of the gas.

A further object of the invention is to provide for suiciently rapid conduction ofthe earth heat to an expansion and storage coil and the pressure regulators so as to maintain the temperature above. the` freezing. point.

A further object of the'invention isl to prdvide the apparatus with a settling tube for trapping condensed fuel and effect revaporization thereof so that only fuel in gaseous state can reach the fuel consuming appliances.

It is also an object of the invention to proshould pass the vaporizing equipment.

In accomplishing these and other objects of the invention, as hereinafter pointed out, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawings, wherein:

Fig. 1 is a diagrammatic section through a liquefied petroleum gas apparatus embodying the features of the present invention.

Fig. 2 is a horizontal section through the vaporizing unit of the apparatus on the line 2-2 of Fig. 1. y

Fig. 3 is an enlarged sectional view through the settling tube, particularly illustrating the float valve for closing the outlet when an eX- cessive amount of liquid accumulates in the settling tube.

Fig. 4 is a fragmentary section through the upper portion of the settling tube, the safety valve and service pipe line connected therewith.

u Fig. 5 is a fragmentary section through the blow-off valve for discharging liquid from the bottom of the settling tube.

Referring more in detail to the drawings:

l designates a liqueed petroleum gas apparatus constructed and installed in accordance with the present invention for supplying a dry gaseous fuel for domestic purposes in communities Where ordinary gas is not available.

In carrying out the invention, l provide a vaporizing apparatus whereby the liquefied petroleum gas such as butane is supplied in readily handled bottles or cylinders 2 which may be lled at a remote station, transported to the point of use, and readily connected to the vaporizing apparatus. Each bottle, therefore, includes a liquid draw-off tube 3 having its inlet located near .the bottom of the bottle vand its discharge end Extending laterally of the passageway 3U is a l* port 33 provided with an annular seat 3d for a liquei'ied gasthrough the inlet i of the draw-oli tube for flow through the pipe "l so that only liquid is supplied from the bottle to the Vaporizing apparatus 8 andV the resulting gas is of sub-V stantially uniform caloriic value. Y

Since conversion of the liquefied gas: to a vapor is commensurate with temperature and pressure, the vaporizing apparatus includes a pressure reducing regulator i i maintained at a substantially constant temperature Vabove the boiling point of the liquid at the pressure to which the regulator is set. I therefore provide for placement of the vaporizing apparatus below ground and utilize heat ofthe earth for maintaining temperature of the fuel above the boiling point at the pressure set by the regulator as I have found that the earth heat is substantially uniform throughout the seasons and for practical purposes provides sufficient heat, when properly applied, to maintain 'the desired vaporizing temperature.

While the earth oii'ers suiiicient heat to supply the heat of vaporization, it is dimcult to transmit the-heat withV sufficient rapidity to prevent the reirigerating eiiect'of the expanding fuel from freezing up of the pressure regulator Yand inter-- tering with iiow oi the fuel. In overcoming this diiculty I provide a tank l2 which is buried in the groundl i3 and adapted to contain the vaporizing and gas storage apparatus at a distance below' the surface `oi the earth Where substantially uniform temperatures are maintained throughout the seasons of the year.

In the illustrated instance the tank includes a cylindrical wall M.. a bottom i5, and an open Y top it adapted to be closed by an insulated door s or closure il. which is seated onan annular ledge projecting inwardly of the wall lli.V In placement of the tank, the earth is compacted into intimate contact with the wall of the tank so that the heat of the earth is readily transmitted to the tank and through the tank tothe interior thereof.

Supported in the tank is an expansion and gas storage element le in the form of a helical coil ci pipe having its upper and inlet end '2Q connected with the outlet side oi rthepressure regulatorV lai, the inlet connection 2l of which is connected with the pipe l' previously mentioned, as shown in l. .The pressure regulator isY set so that the pressure of the liquefied'. gas flowing through the pipe l `is reduced sufficiently to ciect vaporization thereof at the Ltemper'attire carried in the tank, whereby the fuel is passed into the coil i9 in vapor or gaseous iorrn and discharged through the lower and outlet end 22 thereof through a riser pipe 23 having its upper end connected with the upperend of a settling tube 22. The settling tube 2d;- is 'of sucient length to extend substantially to the bottoni of the tank and forms a liquid collecting sump 25.

Y ing appliance.

valve which is retained seated responsive to pressure of a spring 36vv bearing against a cap El to which is connected the vent pipe 28. spring has sufficient capacity to maintain the valve 35 seated under safe pressures in the apparatus, but should the. pressure become excessive the spring will yield to allow blow-oit through the vent pipe 28. The outlet of the low pressure reducing valve is connected by a pipe 33 leading through the wall of the tank and connected with the upper end of a condensate collecting tube 39 located exteriorly ofthe tank and imbedded in the earth at sulicient depth so that vaporizing temperatures are maintainedtherein. The upper end of the condensate collecting tube is also connected with the gasV supply line iti upwardly to the gasv consuming appliance such a cooking stovel.A Y

In order to assuredrainage of condensation occurring in the pipe 4G, the horizontalruns thereof are sloped downwardly to the condensate collecting tube whereby any condensation drains into the tube and collects in the bottom thereof, as at Y42, where it is revaporized by ground temperatures and returned as a gas to the pipe Gil.

In order to provide a suii'ciently rapid conduction of heat Vfrom the groundto the pressure regulator so as to avoidV refrigeratlng eiect of the expanding fuel and prevent freeze-up thereof, I lill the tanksubstantially tothe level of the top of the regulator l I with a heat transfer medium, such as a body ofV liquid, for example, water 3, which also covers the coil mand settling tube 2t. Thus the body of Water serves as a conductor for rapidly collecting and Y conducting heat of the earth to the vaporizing equipment so as to maintain the temperature'thereof above the Vaporizing point of the liqueed gas and prevent'freezeups which might `occur at times of heavy demands on thek equipment. With this arrangement, the settling tube is also kept above the vaporizing temperature 4of the gas so that should any liquid pass the regulator ll and collect in the bottom 25 of the settling tube 24`itY will immediately be vaporized and 1 passed loli in the form of gas through the low pressure regulator 32 tothe heat- In order to provide an additional safety feature and prevent ooding of the outlet piped@ with liquid, I have provided the outlet of the tube with a shut-oir valve 44 adapted to be operated by a ffloat having'co'nnection-'with one arm 46 or a bell-crank lever 41 through a stem 48, the bellcrank lever being pivoted in a recess de of the valve bodyy ona pin 5l'. VThe other arm 52 of The upper end of the tube is providedl with aV gas discharge connection 25 which includes a safetyrvalve 2l having connection with a vent pipe 28. Y

Specically, the outlet connection and safety valve includesV a common fitting 2g having a gas passageway 3S connecting the` settlinggtube with a pipe Si leading to a low pressure control vreguiator 32 which reduces pressure of the gas to that suitable for use in the fuel consuming appliances;

the bell-crank engages against a valving member 53 which is adapted to close a port 54 directly connected-with the tube outlet. Thus when liquid accumulates, as shown in Fig. 3, the float rises to close the valve and'prevent discharge oi' liquid.

If, for some reason, the safety appliances above described should fail to work and liquid fuel be discharged tliroughtheppipe 38, it will be trapped in the condensate collecting tube.

In order tof discharge any excessive amount of liquid that may collect in the settling tube 2t, the lower endithereof is connected with a blow-oir or pressure testing tube 55 extendingV upwardly within the Vtank l2 toja point above the level of the water where it is provided with a valve 56, normally fretained seated responsive to a spring 5l but which is adapted to be readily unseated by TheV pressure applied to a plunger 58 projecting through the discharge port 59 of the valve housing E0.

In operating an apparatus constructed and installed as described, the bottles 2 containing the liquefied gas are connected with the pipe l by the union 5. The valve 5 is then opened so that the vapor pressure in the bottle discharges the liqueed gas through the draw-off tube yto the pipe l Where the liquefied gas ows to the high pressure regulating valve Il, the regulating valve having been set to reduce the pressure sufficiently to effect vaporization of the fuel at the temperature of the body of Water contained in the tank I2. Since the heat of the earth is transmitted to the body of Water with suicient rapidity to maintain the temperature thereof above freezing throughout the seasons of the year, frost and ice are prevented from accumulating on the regulator so as not to interfere with successful operation thereof. The vapor or gas flows through the coil I9 Where it is kept in gaseous state by the earth heat transmitted to the coil through the water as a conducting medium. When the gas consuming appliance is lighted, the vapor flows from the coil through the settling tube, through the low pressure regulator Wherethe pressure is further reduced, and through the pipes 38 and 40 to the appliance. Any liquid which may pass the high pressure regulating valve H or condense in the coil IS will gravitate into the bottom of the settling tube 2d, leaving a dry gas to flow to the low pressure regulator and to the heating appliance. .es above pointed out, any condensate occurring in the lines 38 and 40 will drain into the tube 39. Should it become necessary to remove liquid accumulating in the settling tube 24, this may be readily effected through the blow-off Valve 56.

From the foregoing it is obvious that I have provided a method and apparatus for supplying a liqueiied petroleum gas such `as butane in vapor form to gas consuming appliances and that due to the fact that only liquid is discharged from the bottle or high pressure containers to the vaporizer, the resulting vapors have a substantially uniform calorilc value. Therefore the heating appliance operates with a constant valve setting and air mixture, giving a steady and uniform iiame.

What I claim and desire to secure by Letters Patent is:

1. A liquefied .petroleum gas vaporizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage element in the tank and having an inlet and an outlet, a pressure regulating valve connected with the inlet of the expansion and gas storage element, a supply duct-connected with the pressure regulating valve, means Vconnecting the supply duct with a source of liquefied petroleum gas located above ground, and a body of heat transfer liquid in the tank in contact with the regulating valve and expansion and gas storage element to conduct earth heat from the tank to the regulating valve and expansion and gas storage element. 2. A liqueiied petroleum gas vaporizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage element in the tank and having an inlet and an outlet, a pressure regulating valve connected with the inlet of the expansion and gas storage element, a Supply pipe connected with the pressure regulating valve, means connecting the supply pipe with a source of liquefied petroleum gas located above ground, a body of heat transfer liquid in the tank in contact with the regulating valve and said expansion and gas storage element to conduct earth heat from the tank to the regulating valve and expansion and gas storage element, a settling tube connected with the outlet of the expansion and gas storage element and submerged in said liquid, a low pressure reducing valve connected with the settling tube, and a gas discharge pipe connected with the low pressure reducing valve.

3. A liquefied petroleum gas vaporizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage coilr in the tank and having an inlet and an outlet, a pressure regulating valve connected with the inlet of the expansion and gas storage coil, a supply pipe connected with the pressure regulating valve, means connecting the supply pipe with a source of liquefied petroleum gas located above ground, a body of heat transfer liquid in the tank in contact with the regulating valve and said expansion and gas storage coil to conduct earth heat from the-tank to the regulating Valve and the expansion and gas storage coil, a settling tube connected with the outlet end of the expansion and gas storage coil and submerged in said heat transfer liquid, a low pressure reducing valve connected with the settling tube, a gas discharge pipe connected with the low pressure ,reducing valve, and means connected With the discharge pipe eXteriorly of the tank for collecting condensate occurring in said pipe.

4. A liqueiied petroleum gas vaporizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage coil in the tank having an inlet and an outlet, a pressure regulating valve connected with the inlet of the expansion and gas storage coil, a supply pipe connected With the pressure regulating valve, a liquefied petroleum gas retaining receptacle located above ground, a draw-off tube extending into the receptacle to the bottom thereof for discharging liquefied petroleum gas under pressure of vapor contained in the upper portion of said receptacle, means connecting the draw-off tube with the supply tube, and a body of heat transfer liquid in the tank in contact with the regulating valve and expansion and gas storage coil to conduct earth heat from the tank to the regulating valve and the expansion and gas storage coil, said heat transfer liquid being separate from the liquid hydrocarbon to be vaporized when the apparatus is used.

5. A liquefied petroleum gas vaporizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage coil in the tank having an inlet and an outlet, a pressure regulating valve connected with the inlet of the expansion land gas storage coil, a supply pipe connected With the pressure regulating valve, a liquefied petroleum-gas retaining receptacle located above ground, a draW-oif tube extending into the receptacle to the bottom thereof for discharging liquefied petroleum gas under pressure of vapor contained in the upper portion of said receptacle, means connecting the draw-off tube with the supply tube, a body of heat transfer liquid in the tank in contact with the regulating valve and the expansion and gas storage coil to conduct earth heat from the tank to the regulating-valve and the expansion and gas storage coil, a settling tube connected with the outlet end of the expansion and gas storage coil and submerged in said liquid, a low pressure reducing valve connected with the settling tube, and a gas dis- 7l charge pipe connected with thellow pressure reducing valve. Y

6. A liquefied petroleum gas vaporiZi-ng apparatus including, an expansion and gas storage coil, means supporting said coil Within a temperature zone sufficient for supplying heat to eiect Vaporization of liquefied `petroleum, gas under a predetermined pressure maintained in said coil, a pressure regulating Valve connected with the expansion and gas storagejcoil for maintaining said predetermined pressuregfa source of liquefied petroleum gas connected with the pressure 'regulating valve, a settling tube located within said heat Zone and connected with the expansion and gas storage coil for collecting liquidi passing the regulating valve and having a gas outlet, a gas discharge pipe connected,y with the gas outlet, and a float valve controlling said outlet.

7. A liqueied petroleum gas vaperizing apparatus including, a tank buried under ground to receive earth heat, an expansion and gas storage coil in the tank, a pressure regulating Valve connected withthe inlet of the expansion and gas storage coil, a Supply 'pipeV connected with the pressure regulating valve, means connecting the supply pipe with a source of liqueiied petroleum gas located above ground, a body of heat transier liquid in the tank in contact with the regulating valve and the expansion and gas storage coil to conduct earth heat from the tank to the regulating valve and Ysaid expansion and gas storage coil, and a liquid settling'tube connectedv with the expansion and gas storage coil and located in the tank and submerged in said Vheat transfer liquid.

8. A liqueiied petroleum gas vaporizing apparatus including, a tank buried Vund'erground^ toV receive earth heat, an expansion and gas storage element the tank and having aninlet and an outlet, a pressure regulating valve connected liquid contents of, thetank, conduit.V means or'v supplying the regulator with a liqueed petroleum gas in its liquidphase, a second conduit means connected to the regulator and extend,- ing from said regulator toY a point of use including a coil submerged in said liquid contents, and means foi Ainsulating the regulator from heat exchange with atmosphere.`

12. A method of dispensing liquefied petroleum gas as a gas including storing/a quantity oi liquefied petroleum under pressure at above ground temperature, withdrawing the liqueed petroleum from storage, Vaporizing the withdrawn liquened petroleum gastl by reducing the pressure of the liquefied petroleum gas while in directY heat .exchange contact with the upper portion of a bodj, of heat exchange liquid which is independent of the stored liquefied petroleum gasand warmed directly and solely by earth heat for converting the withdrawn liquened petroleum t-o a Vgas without mixture with said. heat exchange liquid, storing the gas within the body c of heat exchange liquid Without mixture with with the inlet of the expansion and gas storage Y element, means connecting the pressure regulating valve with a Ysource oi liquid' petroleum gas, and a body'o heat transfer liquid in the tank in contact with the regulating valve and said expansion and gas storage element to conduct earth heat from the tank to the regulating valve and said expansion and gas storage Velement. Y

9. A liqueiied petroleum gas vaporizingV apparatus including a tank buried underground to receive earth heat, an expansion and-gas-storage element in the tank, a pressure regulating valve in the tank and connected with the expansion and gas storage element, a liquefied petroleum gas supply pipe connecting the pressure regulating valve with a liquefied petroleum gas supply located above ground, a body of heat trans'- ier liquid in the tank in Contact with the regulating valve and said expansion and gas storage element to conduct Vearth heat from the tank to the regulating valve andv said expansion and gas storage element, a discharge pipe connected with the expansion and gas storage element, and a low pressure regulating valve interposed between the storage element and said discharge pipe.

10. A liqueed petroleum gas Vaporizing apparatus including a tank buried underground to receive earth heat and having abodyo-f heat transfer liquid therein, an expansion'and vaporizing coil in the tank in heat exchange relationship with the liquid contained in said tank, a pressure reducing valve within the confines of the tank in position to Vreceive heatfrom said storage. f

i heat exchange contact with the upper portion ofV a body of'heat exchange liquid warmed di rectly and solely by earthl heat for converting the withdrawn liquefied petroleum to a gas withut mixture with said heatv exchange liquid, storing the gas within lthe body ci heat exchange liquid without mixture withsaid heat exchange liquid, drawing on the stored gas as needed, settling out any unvaporized foreign liquid entrain'ed with thelwithdrawn gas, Yand reducing the pressure of ,the gas withdrawn from said ARTHUR o.v TURNER.

REFERENCESv oirnn The following references are o record in the file of this patent:V

UNITED STATES PATENTS Number Narne Date 1,752,156 Ford Mar. 25, 193) 1,894,497 Rowland Jan. 17, 1933 2,067,720 Y McCombs et val Jan. 12, 1937 2,195,383 V/'hite Jan. 11, 1938 2,233,508 Baird et ai. Mar. 4, 194i Yronmouv PATENTS Y Number v .Country A Date Y2,400,569 Norway MagT 2l, 1946 2,400,570' Norway May 21, 1946 Certicate of Correction Patent No. 2,459,974. January 25, 1949. ARTHUR C. TURNER It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

Column 1, line 52, for the words an the read on the; column 8, list of references cited, lines 71 to 74, inclusive, strike out FOREIGN PATENTS Number Country Date 2,400,569 Norway May 21,l 1946 2,400,570 Norway May 21, 1946 under the heading UNITED STATES PATENTS following line 69, insert 2,400,569 Norway May 21, 1.946 2,400,570 Norway May 21, 1.946

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Ofce.

Signed and sealed this 19th day of April, A. D. 1949.

[IML] THOMAS F. MURPHY,

Assistant Oommssioner of Patents. 

